Semiconductor devices within many electronic instruments have small device geometries, making the devices susceptible to damage from electrostatic discharge (ESD). ESD can cause catastrophic failure of an instrument, latent failures that lower the reliability of an instrument or other types of failures in which instrument performance is degraded. Semiconductor devices in the front-end circuitry of oscilloscopes, spectrum analyzers and other instruments are especially susceptible to ESD damage from electrostatic charges on the cables that are inserted into coaxial connectors at the instruments' input ports.
The incidence of ESD damage can be reduced by discharging each cable before insertion of the cable into the instrument's coaxial connector. Typically, a user of an instrument discharges a cable by momentarily grounding the cable's center conductor to the chassis of the instrument. Since ESD damage can result whenever the grounding of the center conductor is omitted, each user of an electronic instrument must remember to manually discharge each cable prior to inserting the cable into the instrument's coaxial connector. The presence of failures of electronic instruments that are attributable to ESD indicates that relying on a user's mindfulness to discharge cables is not entirely effective in reducing incidence of ESD damage.